Polyvinyl acetal resin sheets containing an alkyl phthalyl ethyl glycollate



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Patented Dec. 26, 1939 UNITED STATES PATENT OFFICE v POLYVINYL ACETAL RESIN SHEETS CON- TAINING AN ALKYL PHTHALYL ETHYL GLYCOLLATE No Drawing. Application February 1, 1938, Serial No. 188,198

4 Claims. (CL 260-36) This invention relates to plastic compositions, and more particularly to compositions coniprising a polyvinyl acetal resin and a conditioning agent.

One object of this .invention is to produce compositions of matter which may be made into permanently transparent, strong and flexible sheets or films of desired thinness which are substantially waterproof, are unaffected by ordinary photographic fluids and possess the desired properties of a support for sensitive photographic coatings. Another object of our invention is to produce compositions of matter which can be made into sheets suitable for use in laminated, shatter-proof glass. Stillanother object is to produce compositions which can be rolled, ex-,

truded, molded or otherwise worked into relatively thick sheets; and massive plastics. A further object is to produce compositions suitable for use in lacquers, artificial silk filaments, wrapping tissues and the like. Other objects will hereinafter appear.

We have *discovered that the alkyl phthalyl ethyl glycollates in which the alkyl group contains -less than three carbon atoms, namely methyl phthalyl ethyl glycollate and ethyl phthilyl ethyl glycollate, are very useful conditioning agents for polyvinyl acetal resins. Not only do they serve as plasticizers in the accepted sense of the term, increasing the flexibility and toughness of polyvinyl acetalresin films, sheets, or other objects or masses containing them, but when used in amounts of about 50 or more parts per 100 parts of certain of the polyvinyl acetal resins, namely the polyvinyl acetal resins in which a predominating proportion of the acetal groups are formaldehyde acetal groups'or butyraldehyde acetal groups, they have an unusual and remarkable effect which we may call elasticizing. That is to, say, a sheet of polyvinyl acetaldehyde or butyralclehyde acetal resin containing about 40 or more parts of methyl or ethyl phthalyl ethyl'glycollate per 100 parts-of resin possesses the property which, in the rubber industry, is known as nerve: namely, the property of stretching to a considerable extent when tension is exerted upon it, and returning to its original dimensions when the tension is released. This property renders such sheets, which we shall call rubbery sheets, particulariy useful in the manufacture of shatter-proof glass.

For the manufacture of cast films or sheets, the polyvinyl acetal resin and methyl or ethyl phthalyl ethyl glycollate may be dissolved in a suitable solvent or solvent mixture, such, for instance, as acetone, methanol, acetone-methanol mixtures, ethylene chloride-methanol mixtures, etc., about 300 to 500 or more parts of the solvent or solvent mixture being used per 100 parts of the resin. From about 3 to 100 parts or more of methyl or ethyl phthalyl ethyl glycollate per 100 parts of resin may be employed, depending determined by experiment. For the manufacture of sheets suitable for photographic film base, from 3 to 25 parts of methyl or ethyl phthalyl ethyl glycollate per 100 parts of resin are suitable. The resin solution is cast as a sheet, the I solvent evaporated, and the sheet stripped from the casting surface.

Sheets for use in laminated glass may be formed by casting, or may be made without the use of volatile solvent by extrusion, for example in the manner set forth in application Serial No. 147,934 of John S. Kimble and Ernest C. Blackard, filed June 12, 1937. For instance, 40 or more parts of methyl or ethyl phthalyl ethyl glycollate'and 100 parts of a polyvinyl formaldehyde or butyraldehyde resin may be mixed in a suitable, jacketed mixer at a low temperature, for example 10 C., and the mixture may then be worked on hot rolls, in the manner described in U. S. Patent 2,048,686 of F. R. Conklin, until complete homogenization has taken place; The

mass thus produced may then be extruded vinyl aliphatic ester and reacting the de-esterification product with an aldehyde in the presence of a de-esterifying catalyst and acetal condensation catalyst. Mineral acids are catalysts for both de-esterification and acetal formation. Among the polyvinyl acetal resins with which methyl and ethyl phthalyl ethyl glycollates are useful may be mentioned, as illustrative 'examples, the polyvinyl formaldehyde acetal resins, the polyvinyl acetaldehyde acetal resins, the polyvinyl formaldehyde acetaldehyde mixed 'acetal resins,'the polyvinyl butyraldehyde acetal resins, the polyvinyl butyraldehyde acetalde hyde mixed acetal resins, and the polyvinyl cyclohexanone butyraldehyde mixed acetal resins.

Examples of the preparation of polyvinyl formaldehyde acetal resins may be found in U. S. Patent 1,955,068, Examples 1, 4 and 5; in U. 8. Patent 2,036,092, Examples 1, 2, 3, 7 and 8; in British Patent 454,691, Examples 1, 2, 3, 4, 5, 6 and 7; in British Patent 404,279, Example 3, and in British Patent 436,072, Examples 1, 2, 3, 4, 5, 6 and 7. Further examples of the preparation of polyvinyl formaldehyde acetal resins are as follows:'

25 lbs. of polyvinyl acetate, the viscosity of whose molar solution (86.08 g. per liter) in benzene was 45 centipoises, was dissolved in 75 lbs. of 70% acetic acid. To this solution wereadded 56 grams of hydroxylamine hydrochloride, for stabilizing the resin, 5.25 lbs. of trioxymethylene, and 6.25 lbs. or 35% HCl. The reaction mixture was allowed to stand for 5 days at 40 C., after which itwas diluted with acetic acid. The resin was precipitated by pouring into cold water, washed, and dried. Analysis showed the resin to have an acetate group content equivalent to 10.6% by weight of polyvinyl acetate and a hydroxyl group content equivalent to 7.1%

by weight of polyvinyl alcohol. The stabilization of polyvinyl acetal resins by hydroxylamine is claimed in the application of Joseph B. Hale, Serial-No. 149,916, filed June 23, 1937, Patent No. 2,146,735.

70 lbs. of polyvinyl acetate, the viscosity of whose molar solution in benzene was 45 centipoises, was dissolved in a mixture of 336 lbs. of glacial acetic acid and 224 lbs.' of water. solution was effected, there we're added a solution or" 318 grams of sodiumnitrite in 500 cc. of water, for stabilizing the resin, 15.2 lbs. of trioxymethylene and 17.5 lbs. of 35% H01. The reaction mixture was allowed to stand for 5 days at 40 (2., whereupon 5 lbs. additional 35% HCl was added and the reaction continued for 6 days longer; a total of 11 days at 40 C.- Thereaction mixture was then diluted with amixture of acetic acid and. ethyl alcohol, and the resin was precipitated by pouring into cold water, washed and dried. Analysis showed the resin to have an acetate group content equivalent to 10.7% by weight of polyvinyl acetate and a hydroxyl group content equivalent to 11.2% by weight of polyvinyl alcohol. The stabilization of polyvinyl acetal resins by nitrous acid is claimed in the application of Charles R. Fordyce and Martti Salo, Serial No. 159,193, filed August 14, 1937, Patent No. 2,159,263.

Examples of the preparation of polyvinyl acetaldehyde acetal resins may be found in U. S. Patent 2,044,730, Example 1; U. S. Patent 1,955,- 068, Example 2; U. S. Patent 2,036,092, Examples 4, 5 and 6; British Patent 466,598, Examples 1, 2,

whose molar solution in benzene was 45 centipoises, was dissolved in 300 lbs. or 95% ethyl alcohol. To this solution were adds-(1'30 lbs; or paraldehyde and 25 lbs. of 35% H]. The reaction mixture was allowed to stand for 4 days at 40 C., after which it was diluted with ethyl al.-

cohol, and the resin precipitated by pouring into After cold water, washed and dried. Analysis showed the resin to have an acetate group content eq'uiv=-* alent to 2.1% by weight of polyvinyl acetate and a hydroxyl group content equivalent to 12.9% by weight of polyvinyl alcohol.

Examples of the preparation of polyvinyl formaldehyde acetaldehyde mixed acetal resins may be found in British Patent 430,136, Examples 1, 2, 3, 4, and 6; British Patent 445,565, Example 2; British Patent 465,873, Examples 1, 2, 3, 4, 5 and 6; French Patent 808,586, Examples 1, 2, 3, 4, 5, 6,12, 13, 14, 15, 16, 17, 18 and 19.

Additional examples of the preparation of polyvinyl formaldehyde acetaldehyde mixed acetal resins are given in the application of Ralph H. Talbot, Serial No. 85,960, filed June 18, 1936 as follows:

"Example 1 100 parts (1.16 mol. calculated as monomeric vinyl acetate) of a polyvinylacetate (45 centipoises), 100 parts of ethyl alcohol, 180 parts of ethyl acetate, 34 parts (.77 mol. as monomeric acetaldehyde) of paracetaldehyde and 5.8 parts (.196 mol. as monomeric formaldehyde) of paraformaldehyde were placed in an enamelled vessel and brought into solution by stirring. When solution was complete, parts of sulfuric acid (sp. g. 1.84) in 10 parts of waterwere added,

and the mixture stirred. The mixture was maintained at a temperature of 40 C. for 144 hours. The contents of the vessel were then diluted with about two and a half volumes of acetone, and the mixture precipitated into water. The precipitated resin was washed free from impurities by repeated changes of cold water, and dried. The resin, when analyzed, gave a hydroxyl group content equivalent to about 6.4 per cent by weight of polyvinyl alcohol, an acetate group content equivalent to about 4.0 per cent by weight of poly- "50 parts (.58 mol. as monomer) of polyvinyl acetate (45 centipoises), 50 parts of ethyl alcohol,

90 parts of ethyl acetate, 17 parts (.385 mol. as

monomer)of paracetaldehyde, 2.9 parts (.098 mol. as monomer) of paraformaldehyde, 5 parts of sulfuric acid and 5 parts of water were treated.

as in Example 1 for 161 hours. The well washed and dried resin gave upon analysis a hydroxyl .group content equivalent to about 9.6% by Weight of polyvinyl alcohol, an acetate group content equivalent toabout 4.1% by weight of polyvinyl acetate, a formaldehyde acetal group content equivalent to about 13.9 per cent'by weight of polyvinyl formaldehyde acetal, and an acetaldehyde acetal group content equivalent to about 69.9 per cent of polyvinyl acetaldehyde acetal.

The polyvinyl acetal portion of the resin was therefore made up of about 18.5 per cent by moles of polyvinyl formaldehyde acetal and 81.5 per cent by moles of polyvinyl acetaldehyde acetal. The resin was soluble in. acetone to an extent which permitted coating a film or sheet from th resin.

Example 3 1300 parts (15.1 mol. as monomer) of a polyvinyl acetate (45 centipoises), 1700 parts of ethyl acetate, 2250 parts of ethyl alcohol (95%) and 48 parts (1.57 mol. as monomer) of paraformale yde (trioxym ylene) were placed in a vessel equipped with a reflux condenser and ameans of agitation, and the contents brought to a temperature of about 70 C. by-means of steam heating. 182.25 parts of sulfuric acid (sp. g. 1.84) dissolved in 51.5 parts of water were added, and the whole was heated at about 70 C. for about five hours, agitating throughout. At this point, 266.4 parts (6.05 mol. as monomer) of paracetaldehyde were added and heating at about 70 C. with agitation was continued for a further period of twenty hours. The contents of the reaction vessel were neutralized with ammonium hydroxide and diluted with water precipitating the resin as a cake. The cake was cut into small pieces and repeatedly washed with hot water until the resin was free from solvents, salts and other impurities. The resin, upon analysis, showed a ,hydroxyl group content equivalent to about 10.1

per cent by weight of polyvinyl alcohol, an acetate group content equivalent to about 3.2 per cent by weight of polyvinyl acetate, the remainder of the weight of the resin being polyvinyl acetal. The polyvinyl acetal portion of the resin was made up of about 80 per cent by moles of polyvinyl acetaldehyde acetal and about 20 per cent by moles of polyvinyl formaldehyde acetal. The resin was not quite soluble inacetone, but could be made to dissolve by admixing small amounts of other solvents. such as alcohols, with the acetone.

Examples of the preparation of polyvinyl butyraldehyde acetal resins may be found in U. S.

Patent 2,044,730, Examples 2, 5 and 6; British Patent 466,598, Example 5; French Patent 813,303, Example 1; French Patent 813,514, Examples 1, 2, 3 and 4; and British Patent 459,878, Examples 1, 2, 5, 6, 7, 8, 9 and 10.

An additional example of the preparation of a polyvinyl butyraldehyde acetal resin is as follows:

23.6 lbs. of polyvinyl.acetate, the viscosity of whose molar solution in benzene was centipoises, was dissolved in 56.5 lbs. of 95% ethyl alcohol. To this solution was added 7.9 lbs. of butyraldehyde and 5.9 lbs. of 35% HCl. The reaction mixture was allowed to stand for 4 days at 40 C., after which it was diluted with ethyl alcohol and acetic acid, and the resin precipitated by pouring into cold water, washed and dried. Analysis showed the resin to have an acetate group content equivalent to 3.1% by weight of polyvinyl acetate and a hydroxyl group content equivalent to 16.3% by weight of polyvinyl alcohoL.

An example of the preparation of a polyvinyl butyraldehyde acetaldehyde mixed acetal resin is given in French Patent 813,303, Example 2..

Examples of the preparation of polyvinyl cyclohexanone butyraldehyde mixed acetal resins are given in British provisional patent application No. 19656/37, dated July 15, 1937, in the name of Kodak Limited, as follows:

cyclohexanone ketal resin 500 g. (5.8 mol.) of polyvinyl acetate, of viscosity 45, were dissolved in 2500 cc. of methyl alcohol and to this mixture were added 1000 cc. of a butyraldehyde acetal 3.3 N. solution of dry hydrogen chloride in methanol and 350 gms. of cyclohexanone. The resultingsolutlon was allowedto stand for 18 hours,

at the end of which time a jelly-like cake had formed. One-half of this solid resinous mass was treated with 350 gins. of butyraldehyde and 500 cc. of methanol. After 24 hours reaction at 40 C., the precipitated resinous mass was removed, dissolved in acetone, and precipitated. The dry material contained 1.0% polyvinyl acetate and 6.42% polyvinyl alcohol. The resin was soluble in a mixture of 90% acetone and 10% methanol, from which it was coated to give a sheet showing unusually low moisture absorption, high flexibility, and moderately low tensile strength. I

"EXAMPLE 22.Polyzn'nyl butyraldehyde acetal cyclohexanone ketal resin 2260 g. of polyvinyl acetate, of viscosity 4s,

were dissolved in 11,325 cc. of methanol, and 3945 tained of the following analysis:

Percent Polyvinyl acetate 2 Polyvinyl a1 mh nl 9.3

"This resinshowed the same general properties as the product of Example 21, i. e., very 10:7 moisture absorption, and high flexibility, but soft and stretchy at elevated temperatures."

What we claim as our invention and desire to be secured by Letters Patent of the United States is:

1. A transparent, rubbery sheet comprising 100 parts of a polyvinyl acetal resin in which a predominating proportion of the acetal groups are selected-from the group consisting of formaldehyde acetal groups and butyraldehyde .acetal groups, and, as a, plasticizer therefor, at least 40 parts, approximately, of an alkyl phthalyl ethyl glycollate in which the alkyl group contains less than three carbon atoms.

2. A transparent, rubbery sheet comprising 100 parts of a polyvinyl formaldehyde acetal resin and, as a plasticizer therefor, at least 40 parts,

approximately, of an alkyl phthalyl ethyl glycollate in which the alkyl group contains less than three carbon atoms.

3. A transparent, rubbery sheet comprising 100 parts of a polyvinyl butyraldehyde acetal resin and, as a plasticizer therefor, at least 60 parts, approximately, of an alkyl phthalyl '.y1 glycollate in which the alkyl group cont .ns less than ing its transparency.

NEIL S. KOCHER. HENRY B. SMITH.

Patent Office CERTIFICATE OFQCORRECTION;

Patent n 2,l8h.,h 6.' December 26, 959- NEIL s. KOCHER, ET AL. It is hereby certified that errorappeers in printed specification of the above m'1mbered patent reqoiring correction as-foliow's Page 3, second column, line 55, claim 2, strike out thewords as a plasticizer there'- for, it least 1 ,0 parts" and insert ihstead-as an eleaxstzlcizei therefor, at least 60 parts; line 59, claim 5, strike" out "as a plasticizer therefor,

at least 60 par-ts", and insert instead. as gnelasticizer therefor, at least 1 0 parts; and that the said Letters Patent should be read'with this correction' therein that the same may conform 'to the record of the case in Signed and sealed this 91m dayiof A ril, A." D. 191 0."

Henry Van hrsdal'e (Seal) hictin'gfcommissioner of Patents.

DISCLAIMER 2,184,426.*Neil S.- Kocher and Henry B. Smith, Rochester, NI Y. PoLmNYL ACETAL Rnsm SHEETS CONTAINING m Amnn Pnmmm Emn GLY- COLLATE. Patent dated December 26 1939. Disclaimer filed December 17, 1941, by the assignee, Eastman Kodak Company. 1

Hereby enters this disclaimer to'claim 2 in itsentirety, and to that portionof claims 1 and-4 reading as follows: selected from the group consisting of formaldehyde aeetal groups and.

[0 Gazette anwy 13; 1942.1 

